import cadquery as cq
w0=cq.Workplane('ZX',origin=(0,-3,0))
w1=cq.Workplane('XY',origin=(0,0,8))
r=w0.workplane(offset=-46/2).moveTo(5.5,-5).box(13,28,46).union(w0.sketch().segment((44,39),(49,42)).segment((44,50)).close().assemble().finalize().extrude(-12)).union(w0.sketch().segment((3,-11),(5,-23)).segment((13,-22)).segment((11,-11)).close().assemble().finalize().extrude(52)).union(w1.sketch().segment((-50,-2),(-22,-2)).segment((-22,-21)).segment((12,-21)).segment((12,32)).segment((10,32)).segment((10,40)).segment((-50,40)).close().assemble().finalize().extrude(-57))